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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <script>
        // var score = prompt("请输入小明的期末成绩：");
        var num1 = +prompt("第一个数：");
        var num2 = +prompt("第二个数：");
        var num3 = +prompt("第三个数：");
        
        alert(typeof num1);

    </script>
</body>
</html>